DID she do it? Did she participate in the or giastic murder of her roommate?

That’s the question hanging over the head of 20-year-old Amanda Knox, the college student and champion soccer player from Seattle who’s been in an Italian prison since the murder of Meredith Kercher, her college roommate, last November in Perugia, Italy.

“48 Hours Mystery” sent the excellent Peter Van Sant and private investigator Paul Ciolino to do their own investigation of the crime that’s gripped two continents.

According to Knox, she spent the night with her boyfriend, doctor’s son Raffaele Sollecito, at his home. (He’s also been charged.) When she arrived home in the next morning, she called her mom in the US to say that it looked like someone had broken in, she couldn’t find her roommates and that Meredith’s door was locked.

The police arrived and broke down the bedroom door to find Meredith’s bloody body.

Because Amanda and Raffaele didn’t act shocked enough or grief stricken enough (they were caught on a store’s surveillance tape the following day buying sexy underwear) plus some blood evidence, the pair were taken into custody. After 14 hours of interrogation without sleep, a lawyer or access to her parents, Amanda blurted out that they’d done it with the help of her boss, Patrick Lamumba.

Trouble is Lamumba, a popular bar owner, had an air-tight alibi – he’d been working at his bar in front of the whole town the whole night. DNA of another man, a dropout and doper, Rudy Guede – whom the kids didn’t know – was also found at the scene. Guede had already taken a powder by then.

Into the mix now comes private investigator, Ciolino, one of the best real-life characters to show up on a TV show in forever. “The whole thing’s a police-generated fairy tale!” Ciolino thunders.

Now he’s somebody you’d want on your side if your kid was charged with murder in a foreign country. Fascinating stuff.